SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cef4969e8c379a6e089dfa8b1094c415ac53aaba54f549620d57c236b7409e1' 
  AND token = 'llXgqryH5oMcaOPNjIhyXtAFTxeWYMkWDPfqumZcV80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}